The present invention relates to a device for measuring distance, in particular for contactless distance measurement, with which a distance between a target object and at least one reference point of the device may be determined, using an emitted measurement signal. The present invention also relates to the operation of a device of this type, in particular a method for operating a digital meter rule.
In the determination of distances, a distinction in made between a direct measurement by making a direct comparison of a distance with a measurement means, e.g., a ruler, a tape-measure, or a folding rule, and by performing an indirect measurement using contactless, e.g., electro-optical distance-measuring devices. Electro-optical distance-measuring devices make it possible to determine distances using transit time or phase measurements of a measurement signal.
The indirect distance-measuring devices on the market are designed nearly exclusively as measuring devices for determining a distance value, and not as auxiliary devices for use to perform actions associated with measurement, e.g., determining and marking points or lines.
Publication EP 15 666 58 A1 makes known a hand-held device for measuring distances that emits transmission beams via optics located in a housing toward the background region of an object to be measured, and then collects the reflected beams. This device also includes a component that is connected with the housing, which may be extended beyond the housing in order to measure short distances in the direction of propagation of the transmission beams. One embodiment of this device provides a component that serves as a spacer and extends beyond the housing by a fixedly predetermined length. The fixedly predetermined length of this spacer is at least as great as the critical distance in front of the housing of the measuring device within which it is not possible to carry out optical measurements on surface areas.